Enneadecagon

From Wikipedia, the free encyclopedia

An enneadecagon.

In geometry, an enneadecagon is a polygon with 19 sides and angles. It is also known as an enneakaidecagon or a nonadecagon. The internal angles of a regular enneadecagon each measure approximately 161.052 degrees, and the area with side length of a is given by

Failed to parse (Missing texvc executable; please see math/README to configure.): A = \frac{19}{4}a^2 \cot \frac{\pi}{19} \simeq 28.4652 a^2.

The radius of the circumcircle of the regular enneadecagon with side length a is

Failed to parse (Missing texvc executable; please see math/README to configure.): R=\frac{a}{2} \csc \frac {180}{19}

(angle measure in degrees)

External links

Eric W. Weisstein, Enneadecagon at MathWorld.

v • d • e Polygons
Listed by number of sides
1-10 sides	Henagon(Monogon) · Digon · Triangle(Trigon) · Quadrilateral(Tetragon) · Pentagon · Hexagon · Heptagon · Octagon · Nonagon(Enneagon) · Decagon
11-20 sides	Hendecagon · Dodecagon · Triskaidecagon · Tetradecagon · Pentadecagon · Hexadecagon · Heptadecagon · Octadecagon · Nonadecagon(Enneadecagon) · Icosagon
Other	Chiliagon · Myriagon